Comparative development, longevity and population growth of exotic and native parasitoids of lepidopteran cereal stemborers in Kenya

2001 ◽  
Vol 91 (5) ◽  
pp. 347-353 ◽  
Author(s):  
J.C. Mbapila ◽  
W.A. Overholt

AbstractStudies on the effect of temperature on the development, longevity and population growth of Cotesia flavipes Cameron and Cotesia sesamiae (Cameron) indicated that the development of both Cotesia spp. from oviposition to cocoon formation and adult emergence was inversely to temperature. The longevity of the parasitoids was also inversely related to temperature. Both parasitoids lived longer when moisture and food (agar + honey/water) were provided. The mean number of females and total adult progeny produced by C. flavipes on two host were, in most cases, higher than C. sesamiae. The intrinsic rate of natural increase of C. flavipes was higher than that of C. sesamiae.

1986 ◽  
Vol 118 (10) ◽  
pp. 1063-1072 ◽  
Author(s):  
D.B. Orr ◽  
J.S. Russin ◽  
D.J. Boethel

AbstractThe behavior, reproductive capability, and longevity of Telenomus calvus Johnson, a phoretic egg parasitoid of the spined soldier bug, Podisus maculiventris (Say), were examined in the laboratory. Telenomus calvus females were observed at 25 different locations on hosts’ bodies; preferred sites were pronota and femora. Attachment to hosts was facilitated by greatly enlarged arolia. Parasitoids dismounted from hosts at the time of oviposition to parasitize egg masses. Production of female progeny by parasitoids in phoretic association with hosts peaked on the 1st day after adult emergence, then declined steadily until day 6; male progeny production remained relatively low and constant over the same period. The mean (± SE) number of progeny produced by T. calvus females was 22.4 ± 3.0. Such a small egg complement enabled most females not in phoretic association, and presented with a fresh egg mass daily, to oviposit all or nearly all of their eggs in the first host egg mass encountered. The intrinsic rate of natural increase for T. calvus in phoretic association was estimated as 0.149 ♀ ♀−1 day−1, resulting in a doubling time of 4.65 days. Longevity on non-ovipositing females with access to honey was 33.7 ± 1.1 days, but declined sharply to 5.7 ± 0.4 days when in phoretic association with hosts. Pre-imaginal development of T. calvus was restricted to host eggs that were ≤12h old, despite continued observed oviposition attempts in older host masses. These results are discussed with regard to the biology of T. calvus as a phoretic parasitoid and to its importance as a parasitoid of P. maculiventris in Louisiana.


1995 ◽  
Vol 16 (1) ◽  
pp. 17-25 ◽  
Author(s):  
M. M. El-Shazly

AbstractThe effects of temperature on the life history of Spilostethus pandurus (Scopoli) were examined by determining the different developmental and reproductive parameters with respect to days of hatching, oviposition, and adult emergence of insects reared in field cages at Giza, Egypt. Hatching, oviposition, and adult emergence continued all year round; the average daily temperature in the coldest month (January) seemed to be above developmental thresholds for different stages. This lygaeid completed six overlapping generations in 1 year. The basic population parameters, i.e. net reproductive rate (R0), gross reproductive rate (GRR), instantaneous rate of natural increase (r), finite rate of natural increase (λ), and mean generation time (T) exhibited a more or less cyclic pattern in successive generations. The highest value of r (rmax) was considered as the intrinsic rate of natural increase of this species.


1977 ◽  
Vol 109 (2) ◽  
pp. 277-284 ◽  
Author(s):  
A. Campbell ◽  
M. Mackauer

AbstractThe effect of temperature on the age-specific fecundity and the survival of apterous and alate virginoparous pea aphid, Acyrthosiphon pisum (Harris), from Kamloops, B.C., was measured. Demographic statistics were estimated for 10.3°, 14.8°, 19.7°, 26.1°, and 27.8°C constant and for fluctuating field temperatures. On a 24-h-day time-scale, temperature and longevity were inversely related in both morphs; total fecundity was highest at average and low constant temperatures. On a physiological time-scale, the intrinsic rate of increase (rm) was insensitive to changes in constant temperature in the range between 10° and 20°C; temperatures above 25°C were detrimental to aphid population growth and survival. Alate virginoparae generally had a longer pre-reproductive period and achieved a lower mean total fecundity than apterae maintained under identical conditions. The usefulness of laboratory measurements for the prediction of population growth under variable field temperatures is discussed. Differences in the reproductive patterns of alate and apterous pea aphids are considered in the context of the r- and K-hypothesis of selection.


1981 ◽  
Vol 29 (1) ◽  
pp. 25 ◽  
Author(s):  
PL Walker

Age-specific life and fecundity studies on the weevil Phlyctinus callosus (Boh.) (a polyphagous pest in gardens in parts of southern Australia, especially Victoria) revealed that mortality was greatest in the immature stages and that high temperatures were lethal to eggs (>30 deg C) and larvae (>25 deg C). The intrinsic rate of natural increase was greatest at 20 deg C, and the greater proportion of its value was accounted for early in the egg-laying period. Larvae could be reared on carrot roots in the laboratory; 76% of larvae reared in this manner to the pupal stage passed through 7 instars, 12% through 6, and 12% through 8. Head-capsule width was a suitable criterion for identifying the instars. Eggs could be stored for as long as 12 weeks at 5 deg C with no loss of viability. These results are discussed in relation to control measures against the weevil.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260499
Author(s):  
Yobana A. Mariño ◽  
Paul Bayman ◽  
Alberto M. Sabat

The coffee berry borer (CBB) Hypothenemus hampei Ferrari is the most serious pest of coffee worldwide. Management of the CBB is extremely difficult because its entire life cycle occurs inside the fruit, where it is well protected. Knowing which life stages contribute most to population growth, would shed light on the population dynamics of this pest and help to improve CBB management programs. Two staged-classified matrices were constructed for CBB populations reared in the lab on artificial diets and CBB populations from artificial infestations in the field. Matrices were used to determine demographic parameters, to conduct elasticity analyses, and to perform prospective perturbation analysis. Higher values of the intrinsic rate of natural increase (rm) and population growth rate (λ): were observed for CBB populations growing in the lab than in the field (rm: 0.058, λ: 1.74 lab; rm: 0.053, λ: 1.32 field). Sensitivity values for both CBB populations were highest for the transitions from larva to pupa (G2: 0.316 lab, 0.352 field), transition from pupa to juvenile (G3: 0.345 lab, 0.515 field) and survival of adult females (P5: 0.324 lab, 0.389 field); these three vital rates can be important targets for CBB management. Prospective perturbation analyses indicated that an effective management for the CBB should consider multiple developmental stages; perturbations of >90% for each transition are necessary to reduce λ to <1. However, when the three vital rates with highest sensitivity are impacted at the same time, the percentage of perturbation is reduced to 25% for each transition; with these reductions in survival of larvae, pupae and adult females the value of λ was reduced from 1.32 to 0.96. Management programs for CBB should be focused on the use of biological and cultural measures that are known to affect these three important targets.


2020 ◽  
Vol 25 (3) ◽  
pp. 525-537
Author(s):  
Fatemeh Jafarian ◽  
Shahriar Jafari ◽  
Yaghoub Fathipour

Eotetranychus frosti (McGregor) (Tetranychidae) is a main pest of apple and some fruit trees in Iran. The life table parameters of E. frosti on seven apple cultivars (Red, Golab Kohanz, Gala Imperial, Gala Royal, Fuji, Granny Smith and Golden) at 27±1ºC, 50±10% RH and a photoperiod of 16: 8 (L: D) h were determined. The immature developmental times of E. frosti ranged from 6.50 days on Granny Smith to 18.31 days on Golab Kohanz. The lowest and highest survival rate for whole immature stages was 85.71% and 95.72% on Golab Kohanz and Red, respectively. Fecundity of E. frosti was affected by cultivars; varied from 60.43 eggs on Golab Kohanz to 110.19 eggs on Granny Smith. The intrinsic rate of natural increase (r) varied significantly among different cultivars in which the lowest value (0.119 day-1) was on Golab Kohanz and highest value (0.365 day-1) was on Granny Smith. The mean generation time (T) was shortest on Granny Smith (11.45 days) and longest on Golab Kohanz (30.09 days). According to the results, Granny Smith and Golab Kohanz were susceptible and resistant cultivars, respectively among the ones tested. The findings of this study provide new information that can be used to design a more comprehensive IPM program for this important pest.


2016 ◽  
Vol 66 (3-4) ◽  
pp. 335-345
Author(s):  
Eliza Pourtaghi ◽  
Asghar Shirvani ◽  
Maryam Rashki

Aphids can have devastating effects on agriculture and horticulture, and biological control agents form an important means of controlling them.Aphidius matricariaeHaliday is an important endoparasitoid for the suppression of aphid pest population outbreaks. In this research, the influence of three different temperatures, 20, 25 and 30°C, on some life cycle charactersitic ofA. matricariaewas studied under laboratory conditions when present on its host,Aphis fabaeScopoli. At 30°C, the intrinsic rate of increase, net reproductive rate, finite rate of increase, mean generation time and increase rate in one week were all significantly lower compared to the lower temperatures. The results showed that temperature had a significant effect on the duration of parasitoid development from oviposition to adult emergence. Moreover, the value of doubling time was higher at 30°C than at 20 and 25°C. The parasitoid had the shortest longevity, life span and lowest fecundity at 30°C. This investigation of temperature-dependent development and reproduction can help in the management of biological control programs. The results of this study demonstrate thatA. matricariaeis able to perform, and be mass produced, as a favorable and proper natural enemy for the biocontrol ofA. fabaeat a temperature range of 20-25°C.


1991 ◽  
Vol 69 (5) ◽  
pp. 1189-1193 ◽  
Author(s):  
L. B. Smith ◽  
P. S. Barker

The effect of temperature on development time, oviposition, and mortality of the sibling species Tribolium audax Halstead and Tribolium madens (Charpentier) was investigated in the laboratory. The mean development times of T. madens, not including slow-developing larvae, ranged from 54 days at 25 °C and 75% RH to 24 days at 35 °C and 75% RH. The corresponding mean development times for T. audax were 50.5–27.4 days. At 25 °C and below, the larvae of each species separated into two groups, one continuing to the adult stage and the other entering a resting stage. The resting stage could not be broken by a period of 2 weeks at −5 °C. The slow-developing larvae required 4 to 5 times as long to complete their development as those that developed rapidly. Slow-developing larvae of T. madens that had been at 17.5 °C and 75% RH for 658 days, and of T. audax that had been in the same conditions for 908 days, could complete development when placed at 27.5 °C and 75% RH. Peak oviposition for T. madens occurred at 17 weeks after adult emergence at both 27.5 and 30 °C; the total oviposition period was 47 weeks at 30 °C and 60 weeks at 27.5 °C. Peak oviposition for T. audax occurred at 6 weeks at both 27.5 and 30 °C; the total oviposition period was 36 weeks at 30 °C and 59 weeks at 27.5 °C. Larval and pupal mortality was low at 25 °C or above in T. madens and T. audax. Below 25 °C the survival rate of T. madens was somewhat higher than that for T. audax.


2009 ◽  
Vol 61 (2) ◽  
pp. 329-336 ◽  
Author(s):  
Shila Goldasteh ◽  
Asghar Talebi ◽  
Yaghoub Fathipour ◽  
Hadi Ostovan ◽  
Abbasali Zamani ◽  
...  

The development, life history, reproduction, and population growth parameters of Planococcus citri Risso on coleus [Solenostemon scutellarioides (L.) Codd.] were studied at various temperatures ranging from 10 to 37?C, 70?10% RH, and photoperiod length of 16: 8 h (L: D). Females and males successfully developed into adults at from 15 to 32?C and 18 to 32?C, respectively. All first instars died at 10, 12, and 37?C. Lower temperatures (10, 12, and 15?C) caused higher egg mortality than did higher temperatures (32, 35, and 37?C). At all temperatures (except 15?C), the highest percentage of nymphal mortality was observed in the first instar. The sex ratio was female-biased between 15 and 30?C, but there was a slightly higher number of males at 32?C. The highest adult longevities of females and males were obtained at 18 and 25?C, respectively. The pre-oviposition, oviposition, and post-oviposition periods were significantly different at various temperatures. The highest fecundity was observed at 23?C. The shortest and longest oviposition periods occurred at 32 and 18?C, respectively. Maximum values of the intrinsic rate of natural increase (rm), net reproduction rate (R0), and finite rate of increase (?) and the shortest mean generation time (T) and doubling time (DT) were obtained at 25?C. Our findings showed citrus mealybug performances to be highly affected by temperature.


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