Natural Mortality of Erioischia brassicae (Bouche) (Diptera, Anthomyiidae) During the Immature Stages of the First Generation

10.2307/2080 ◽  
1959 ◽  
Vol 28 (2) ◽  
pp. 231 ◽  
Author(s):  
R. D. Hughes ◽  
Dorothy D. Salter
2017 ◽  
Vol 10 ◽  
pp. 11 ◽  
Author(s):  
E. T. Stratopoulou ◽  
E.T. Capatos

The phenology of the population of immature stages of pear psylla, Cacopsylla pyri (L.), was studied in Greece (region of Magnesia), during the period 1988-1991 and it was found to follow a basic pattern. Pear psylla produces 5-6 gencrations per year. The first generation develops during the period February-middle April and it is quite discrets. Three overlapping generations are developed during the period front middle April until middle August but the amount of overlapping varies front year to year. Front middle August until the end of the season pear psylla produces 1-2 generations, i.e. only a part of the firth generation complotes the sixth one. Population density is generally low during the first generation but during May-June reaches verty high levels. During sommer, strong environmental pressure, supresses the population of pear psylla to low levels but it recovers again during September-October.


1958 ◽  
Vol 90 (12) ◽  
pp. 720-721 ◽  
Author(s):  
Wm. L. Putman

Every spring since it was first noticed in 1947, the first-generation immature stages of the European red mite, Metatetranychus ulmi (Koch), has suffered some mortality in peach orchards of the Niagara Peninsula of Ontario. Sometimes this mortality was negligible but in the cold, wet spring of 1949 it reached 80 per cent in some orchards. Mortality of similar extent has not been noticed on other hosts of the mite at this season; counts of a thousand or more living and dead mites on young shoots of each host at Vineland Station on May 16, 1957, showed apparent mortalities of 53 per cent on Elberta peach, 7 per cent on Italian prune, and 8 per cent on Melba apple. The mortality on peach leaves is difficult to determine, for if the mites are examined too early, many of those killed in the quiescent, premoulting condition cannot be distinguished from living ones, and if they are examined too late, the survivors may have suffered mortality from other causes.


Zootaxa ◽  
2010 ◽  
Vol 2495 (1) ◽  
pp. 53 ◽  
Author(s):  
VALERIA C. ONOFRIO ◽  
MARCELO B. LABRUNA ◽  
JOÃO LUIZ H. FACCINI ◽  
DARCI M. BARROS-BATTESTI

The tick Ixodes luciae occurs in many countries within the Neotropical region but only adult ticks have been morphologically described. Larvae and nymphs parasitize marsupials and rodents while adults are common on marsupials. A colony of I. luciae was obtained from females collected on marsupials from the State of Rondônia, Northern Brazil. After being fed on rabbits, the specimens were maintained under controlled conditions of temperature and humidity. Unfed larvae, nymphs, males and females of the first generation were cleaned and prepared for both optical and scanning electron microscopy. Ixodes luciae is closely related to Ixodes loricatus, Ixodes schulzei, and Ixodes amarali, although each species has its own array of distinctive characters. The larva of I. luciae differs from those of both I. schulzei and I. amarali in the length of the capitulum and from I. schulzei in the number of posthalleral setae in the Haller’s organ. Nymphs differ from I. amarali, I. loricatus and I. schulzei by the length of the external spur on coxae I, and from I. schulzei and I. amarali in having slender and shorter capitulum and hypostome. Males and females of I. luciae differ from the other three species by the length of the external spur on coxae I and by the scutal punctations, which are much longer and larger, respectively, in I. luciae. However, except for a few features, the chaetotaxy is the same for larvae of the four species, not only on the idiosoma (e.g. scutum with four pairs of setae), palpi and tarsus I, but also the number of porose setae within the capsule of Haller’s organ and the prehalleral setae.


2012 ◽  
Vol 22 (7) ◽  
pp. 837-854 ◽  
Author(s):  
Fátima M. Gonçalves ◽  
M. Conceição Rodrigues ◽  
José A. Pereira ◽  
Howard Thistlewood ◽  
Laura M. Torres

2019 ◽  
Vol 20 (3) ◽  
pp. 215-224 ◽  
Author(s):  
Li-jun Cai ◽  
Bao-zhen Hua

The scorpionfly Panorpa qinlingensis Chou & Ran is described and illustrated in detail for its immature stages, including egg, larva, and pupa. The egg is oval with chorion decorated with irregular polygonal network. The larva is eruciform and peripneustic, bearing eight pairs of abdominal prolegs. A pair of prominent compound eyes are present on head. The first instar larva differs from later instars in possessing a prominent egg burster on frons and with clavate setae. The pupa is exarate and decticous, taking the shape of the adults. The scorpionfly is bivoltine, overwintering as prepupal stage in the soil. The durations of the egg, larval, and pupal stages are 5–9 d, 19–27 d, and 8–18 d respectively for the first generation. Adults emerge from mid May to early June and from late July to mid August in the Micang Mountain, central China.


1973 ◽  
Vol 63 (2) ◽  
pp. 347-359 ◽  
Author(s):  
M. W. Service

AbstractThe biology of Anopheles claviger (Mg.) was studied for a varying number of years in three localities in southern England. The fluctuations in the proportions of the larval instars and pupae were studied by weekly sampling throughout the year. The population overwintered from October to April as pre-adults, and in mid-winter larval development was arrested, but was resumed in March. The construction of a simple life-table showed the existence of a large mortality of immature stages during the overwintering period. Females were sampled at two localities by human bait catches, and at one also by insect suction traps. There was an interval of 1–2 weeks between adult emergences in April and blood-feeding, during which time females apparently fed on sugar solutions. Maximum biting densities of nullipars in May and September showed that A. claviger was bivoltine. The physiological age structure of the population showed that most parous adults at bait had oviposited only once or twice, but a few females had laid four batches. Live Hygrobatid-type mites proved reliable in indicating nulliparity. Mature larvae developed in the eggs 5–7 days after oviposition and while most eggs hatched within the next three days, a few remained unhatched until the 30th day. Females of the second generation (September) laid fewer eggs than those of the first generation (May). About six days were required for blood digestion, and females supplied with sugar were able to live 46 days. The marked delays between successive gonotrophic cycles in natural populations would make parous rates unreliable for the estimation of daily mortalities.


2007 ◽  
Vol 60 ◽  
pp. 21-25 ◽  
Author(s):  
X.Z. He ◽  
Q. Wang

This study reports an investigation on the aestivation and overwintering strategies of Platygaster demades an egg parasitoid of apple leafcurling midge (ALCM) Dasineura mali under natural conditions during 2005 2006 The first three generations of ALCM developed into adults during the springautumn of 2005/2006 and the fourth generation overwintered as larvae All first generation P demades emerged in the spring of 2005 About 64 of live individuals of P demades in the second generation and 38 in the third generation entered aestivation as eggs which hatched in mid March and early May 2006 respectively Parasitoid eggs of the fourth generation started to hatch four weeks after the parasitised ALCM larvae entered the soil The aestivated and fourth generation parasitoids overwintered as immature stages and started emerging in late September 2006 The emergence patterns of overwintered parasitoids and ALCM were highly synchronized in the following season


1983 ◽  
Vol 115 (9) ◽  
pp. 1229-1231 ◽  
Author(s):  
H. J. Herbert ◽  
D. Hamilton ◽  
G. Gabor

AbstractIn the first generation brown mite, Bryobia rubrioculus (Scheuten), on apple inhabits the wood as well as the leaves. To eliminate sampling the wood, which is very tedious and time consuming, equations were developed to describe the total population of immature stages and adults from observations of the number of mites on the leaves alone.


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