Growth and development of larvae and adults of Tipula sacra Alexander (Insecta: Diptera) in a series of abandoned beaver ponds

1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.

1968 ◽  
Vol 100 (2) ◽  
pp. 202-206 ◽  
Author(s):  
Louis F. Wilson

AbstractThe willow beaked gall midge, Mayetiola rigidae (Osten Sacken), is univoltine in Michigan. Adults emerge from bud galls on Salix discolor Mühl. and other willows on mornings of warm days in early April. Eggs are laid singly on or near the buds of the host. Head capsule measurements indicate three larval instars. The last two instars each possess a spatula. The first-instar larva emerges in late April and penetrates the soft bud tissues. The gall begins to develop at the beginning of the second instar in mid-May. The third instar appears in early July and continues to enlarge the gall until fall. Prior to overwintering, the larva lines the inner chamber of the gall with silk and constructs one to seven silken septa across the passageway. Pupation occurs in mid-March. The gall deforms the stem and occasionally a galled branch dies or breaks off.


1968 ◽  
Vol 100 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Louis F. Wilson

AbstractThe taxonomic status of Rhabdophaga sp. cannot be determined until a complete revision of the genus occurs. Rhabdophaga sp. on Salix discolor Mühl. is univoltine in Michigan. Adults emerge in mid-April, and shortly afterward deposit numerous eggs on the setaceous undersurface of emerging willow leaves; larval eclosion occurs between 1 and 2 weeks later. Head capsule measurements reveal three larval instars. The first-instar larva bores into the stem until it reaches the pith. Gall development begins about mid-June shortly after the second instar appears. The third-instar larva overwinters in the gall and the pupa appears in early April. The prolate gall is found on the proximal ends of young willow shoots; heavily galled shoots usually die.


1965 ◽  
Vol 97 (9) ◽  
pp. 962-969
Author(s):  
Louis F. Wilson

AbstractThe pine gall weevil has a 3-year life cycle on red pine (Pinus resinosa Ait.) in Michigan. Adults oviposit from June to August, depositing 1 to 10 eggs in a niche chewed in the bark of a branch internode. Larvae first emerge in August, feed as a group toward the cambium, and then radiate out along the xylem. Head capsule measurements from 1585 larvae indicate that there are three larval instars. Gall development begins in June of the second year, shortly after the larvae begin the second instar. The third instar commences in June of the third year. Pupation occurs in May of the fourth season; adult emergence follows in June. Overwintering occurs in the egg stage or in the three larval instars. Adults do not overwinter, and apparently three distinct broods occur in Michigan.


2020 ◽  
Vol 17 (2) ◽  
pp. 104
Author(s):  
Dosma Ulina Simbolon ◽  
Maryani Cyccu Tobing ◽  
Darma Bakti

<p><em>Stenocranus pacificus </em>Kirkaldy (Hemiptera: Delphacidae) is destructive pest on corn plants in South Lampung and it has been reported to cause corn damages in North Sumatra. The  objective of this research was to study some aspects biology of <em>S. pacificus</em> on corn plants in screenhouse. The research was conducted by observing the biology of <em>S. pacificus</em> that was reared on corn plants in screenhouse.<em> </em>The results showed that life cycle of <em>S. pacificus </em>was 38–47 (41,60 ± 3,19) days: egg was 9–11 (10,20 ± 0,79) days, the first instar nymph was 3–4 (3,70 ± 0,48) days, the second instar nymph was 3–4 (3,90 ± 0,32) days, the third instar nymph was 3–4 (3,70 ± 0,48) days, the fourth instar nymph was 3–4 (3,80 ± 0,42) days, and the fifth instar nymph was 3–4 (3,60 ± 0,52) days. Age of female was 13–17 (15,30 ± 1,34) days. It was longer than age of male which was 8–12 (10,10 ± 1,20) days. Female could produce 181–214 (197,60 ± 11,64) eggs during its life. The sex ratio was 1:1,98.</p>


Holzforschung ◽  
2002 ◽  
Vol 56 (4) ◽  
pp. 335-359 ◽  
Author(s):  
P. Oevering ◽  
A.J. Pitman

Summary Pselactus spadix attack of marine timbers was characterised by circular emergence holes 1.48±0.05 mm in diameter and adult tunnels (1.49±0.34 mm) breaking through the wood surface. Larval tunnels measured 0.407–1.892 mm in diameter, initiated from adult tunnels and increased in diameter away from the adult tunnel terminating in frass free pupal chambers (1.6±0.3 mm × 3.5±0.7 mm). Observations of larval tunnel locations indicated oviposition occurred inside the adult tunnels. P. spadix life history was investigated in Scots pine (Pinus sylvestris) heartwood at 22±2 °C and 99±1% r.h. Mean adult longevity was 11.5±6.5 months, with mean post-mating longevity for males (11.7±2.9 months) significantly longer than for females (6.3±1.1 months). Adults of at least 2–3 months old were found mating in galleries, which, with observations of the larval tunnel pattern, indicated P. spadix can complete its life cycle without emerging from wood. Five larval instars were identified by measurement of 1722 head capsule widths and application of Dyar's law. Mean development time from 2nd instar to adult emergence was 70.5±6.9 weeks and pupation took 14.6±5.8 days. Development from 2nd instar to reproductive adult took between 17–20 months, with life cycle approximating 24 months at 22±2 °C and 99±1%


1978 ◽  
Vol 35 (9) ◽  
pp. 1165-1170 ◽  
Author(s):  
Mark D. Morgan ◽  
Alfred M. Beeton

Mysis relicta was sampled in Lake Michigan approximately monthly with an epibenthic sled, August 1975–July 1976. Total numbers ranged from a low of 23 m−2 in February to a high of 337 m−2 in May and averaged 188 m−2. It was possible to partition the population into five instars. Major peaks in proportions of first instar individuals occurred in March, July, and November. It took about 1 yr for first instar individuals to reach the fourth instar. Growth averaged a little less than 1 mm/mo. Males and females reached maturity and bred in the fourth instar, so females produced their first brood at 1 yr of age. Males died at this time, but females were found to molt to the fifth instar, mate, and produce a second brood approximately 4 mo later. Key words: Mysis relicta, Lake Michigan, life history, abundance


2010 ◽  
Vol 19 (3) ◽  
pp. 164-168 ◽  
Author(s):  
Huarrisson Azevedo Santos ◽  
Isabele da Costa Angelo ◽  
Marcos Pinheiro Franque ◽  
Usha Vashist ◽  
Aline Falqueto Duarte ◽  
...  

The current study investigated the biology of nymphs of the first and second instars of Argas (Persicargas) miniatus. Nymphs were deprived of food for 15, 30 or 60 days and held at 27 ± 1 ºC and 80 ± 10% relative humidity (controlled conditions) or at room conditions of temperature and relative humidity. Nymphs of first instar deprived of food for 15 or 30 days molted to second and third instars in both controlled and room conditions. Nymphs of the first instar deprived of food for 60 days had 28 and 37% mortality in controlled and room conditions, respectively; and survivors did not attach to the host. Nymphs of the second instar, deprived of food for 60 days, molted either to the third instar or to males after feeding on Gallus gallus, and the nymphs of the third instar developed to adults (42.42% males and 36.36% females when nymphs were held in controlled temperature and humidity conditions, and 40.54% males and 48.65% females when nymphs were held in room conditions). The remainder of the nymphs molted to the fourth instar and then molted to females. In conclusion, the nymphal starvation period of 60 days determined the number of nymph instars in the life cycle of A. miniatus under the experimental conditions studied.


1967 ◽  
Vol 99 (2) ◽  
pp. 146-159 ◽  
Author(s):  
G. C. Becker ◽  
D. M. Benjamin

AbstractThe specific status of Neodiprion nigroscutum Middleton is firmly established by new data. The adult female is mostly black and brown. The second annulus of the lancet is generally weakly developed ventrally. The larvae have black head capsules in the first instar, but this coloration usually changes to reddish brown in the later instars. The third, fourth, and fifth feeding-instar larvae have unbroken subdorsal and supraspiracular lines, and broken postepipleural lines, but lack an epiproctal spot. The nonfeeding-instar larvae often have a pink body color. The egg mass of most females is green. Jack pine is the preferred host. The fecundity is approximately 100 eggs, but they are typically distributed over many branches, usually in one needle on each branch. Larval colonies composed of first- through fourth-instar larvae usually contain 3–10 larvae, while colonies of fifth-instar larvae usually contain 1–6 larvae. There are two generations per year in southern Wisconsin. Feeding-instar larvae are present in late May and June, and again (second generation) in August and September. The species is distributed throughout the jack pine stands of Wisconsin. Phenological data and notes on parasites are presented.


1993 ◽  
Vol 71 (8) ◽  
pp. 1530-1533 ◽  
Author(s):  
M. Lauzon ◽  
P. P. Harper

The aquatic snipe fly Atherix lantha Webb in the rivière de l'Achigan in the Laurentian foothills of Quebec has a univoltine life cycle. The eggs were laid in great clusters under a small footbridge spanning the river and some 61 000 dead females were observed attached to their egg masses. Upon hatching, the hatchlings fell into the water. There were five larval instars. First-instar larvae appeared in June. Growth was rapid and by September most of the population had reached the fourth instar. Overwintering occurred mainly in the fifth and final instar. On the basis of measurements of the second antennal segment of the larvae, it was concluded that growth follows Dyar's law of constant growth rate between instars (growth rate = 1.31), except between the first two instars, where the growth rate was higher (1.41). In May the full-grown larvae left the river to pupate on the banks and adults were on the wing from mid-May to late June.


2008 ◽  
Vol 43 (2) ◽  
pp. 247-253 ◽  
Author(s):  
Yigen Chen ◽  
John R. Ruberson

Sporadic starvation of herbivorous insect pests, such as the beet armyworm Spodoptera exigua (Hübner), often occurs due to host plant scarcity and dislodgement from host plants resulting from inclement weather, enemy attack, and other perturbations. We hypothesized that (1) starvation of beet armyworm in earlier instars would increase the possibility of undergoing supernumerary instars greater than would be the case for later instars; and (2) starvation of beet armyworm in earlier instars would prolong developmental time more than starvation in later instars. We tested these hypotheses by starving beet armyworm larvae for 48 h in the first, third, and fifth instars, and monitoring their development. Beet armyworms normally have 5 instars before pupation. Significantly more larvae underwent 6 larval instars (20.22 ± 4.35%) when starved for 2 d in the first instar compared with those starved for 2 d in the third (2.0 ± 2.00) and fifth instars (0.0), and relative to unstarved larvae (0.0). The number of instars that S. exigua larvae will experience can be predicted as early as the third instar-head capsule widths in this instar clearly differentiate for those destined to experience 5 and 6 instars. Developmental times of starved larvae also were prolonged compared with unstarved larvae. Developmental times (mean ± SE in days) of larvae starved in the first instar (20.32 ±0.16) were significantly longer than those starved in the third (17.04 ± 0.20) or fifth instars (16.92 ± 0.10), or than unstarved larvae (14.62 ± 0.25). Timing of starvation significantly affected the pupal weight of larvae undergoing 5 instars. This suggests that (1) starvation of 2 d in very early instars (the first instar) increases the pupal weight at the cost of prolonged developmental time; and (2) starvation of 2 d in later instars (the fifth instar) leads to lower pupal biomass, presumably because of inability to compensate for the loss.


Sign in / Sign up

Export Citation Format

Share Document