LIFE HISTORY AND HABITS OF THE PINE CONE WILLOW GALL MIDGE, RHABDOPHAGA STROBILOIDES (DIPTERA: CECIDOMYIIDAE), IN MICHIGAN

1968 ◽  
Vol 100 (4) ◽  
pp. 430-433 ◽  
Author(s):  
Louis F. Wilson

AbstractThe pine cone willow gall midge is univoltine in Michigan. Adults emerge from the galls on Salix eriocephala Michx. and other willows on warm days in late April or early May. Eggs are laid singly on the leaves and stems of the host. Head capsule measurements indicate three larval instars. The first-instar larva emerges in early May and penetrates the soft tissues at the base of the developing shoot tip. Shortly thereafter, the gall begins to develop and is about half grown by the time the second-instar larva appears in late May. The last-instar larva appears in July. Before overwintering, the larva constructs a cocoon which may or may not be closed at the top. Pupation occurs in early April. Numerous inquilines and parasites inhabit the developing and mature gall.

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.


1966 ◽  
Vol 98 (7) ◽  
pp. 777-784 ◽  
Author(s):  
Louis F. Wilson

AbstractThe boxelder leaf gall midge is univoltine in Michigan. Adults emerge after the first few warm days in April, and deposit numerous eggs within the folded young leaves of boxelder (Acer negundo L.). Larval eclosion occurs a few days later, and gall development begins shortly after. Head capsule measurements revealed three larval instars. Third-instar larvae drop to the ground near the end of May, work their way into the soil, and construct cocoons. Pupation occurs in late August, and overwintering takes place in the pupal stage. Because oviposition occurs almost always on leaves in a certain stage of development and an estimated 50% of leaves will therefore escape attack, host mortality apparently cannot be caused by this insect.


Zootaxa ◽  
2017 ◽  
Vol 4238 (4) ◽  
pp. 451 ◽  
Author(s):  
ALBERT DELER-HERNÁNDEZ ◽  
JUAN A. DELGADO

Preimaginal stages of the six species of Hydraenidae presently known from Cuba were obtained by rearing adults in the laboratory. Eggs of Hydraena perkinsi Spangler, 1980, H. decui Spangler, 1980 and H. franklyni Deler-Hernández & Delgado, 2012 are described and illustrated for the first time. The first instar larva of Gymnochthebius fossatus (LeConte, 1855) is redescribed, adding some new remarkable morphological characters including what could be the first abdominal egg-burster reported for this family. All larval instars of H. perkinsi, H. guadelupensis Orchymont, 1923 and Ochthebius attritus LeConte, 1878 are described and illustrated for the first time, with a special emphasis on their chaetotaxy. The second instar larva of G. fossatus along with first and third instar larvae of H. decui and H. franklyni are also studied for the first time. The pupal morphology and vestiture of a species belonging to the genus Hydraena are described for the first time, based on the pupa of H. perkinsi. Biological notes for several preimaginal stages of the studied species are also given. 


1977 ◽  
Vol 109 (8) ◽  
pp. 1121-1128
Author(s):  
Richard D. Medley ◽  
V. M. Carolin

AbstractPreserved material from 1962 field studies provided information on the habits and morphology of the tachinid parasitoid Chaetophlepsis nasellensis Reinhard. Parasitization of the larvae of the western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst), continues over a 30- to 40-day period. Maggots issue from the host larvae and drop to the ground to pupate. The pupae normally overwinter, with adults emerging the following spring or summer. The early first-instar larva differs markedly from the late first-instar. The three instars can be distinguished on the basis of body length and the structure and form of the buccopharyngeal apparatus. The first and third larval instars and the puparium are distinctive enough to permit easy identification during studies of the western hemlock looper and associated loopers.


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.


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%


2020 ◽  
Vol 60 (1) ◽  
pp. 319-332 ◽  
Author(s):  
Yusuke N. Minoshima ◽  
Reiya Watanabe

The morphology of immature stages of Helophorus (Gephelophorus) auriculatus Sharp, 1884 is described. This is the first description of the larva and pupa of the subgenus Gephelophorus Sharp, 1915. We describe the morphology of the egg-case, all larval stages (first to third instar, including chaetotaxy of the head) and pupa. Morphological transformations between larval instars were examined. Head chaetotaxy was nearly identical between instars. Ventral teeth on the nasale, considered as a useful taxonomic character, were absent in the first instar but well developed in later instars. Chaetotaxy differed among the subgenera Gephelophorus, Helophorus and Lihelophorus in the length and shape of setae on head capsule and maxilla. Pupal morphology was similar to that of previously described pupae: H. (Helophorus) aquaticus (Linnaeus, 1758) and H. (Rhopalohelophorus) orientalis Motschulsky, 1860. A key to families of the Hydrophiloidea of Japan based on larval characters is provided.


1976 ◽  
Vol 108 (6) ◽  
pp. 591-600 ◽  
Author(s):  
F. J. H. Fredeen

AbstractThe larvae of Simulium arcticum Malloch in three collections from the North Saskatchewan River of May and June 1969, 1971, and 1974 showed seven instars. The first instar larva possessed an egg burster and the seventh instar larva possessed separated cervical sclerites. The intervening instars, however, could be decisively identified only by measuring the lengths of the postgenae. The observed mean postgenal lengths for all but the seventh instar were near those predicted by the regression line logeY = 4.1216 +.2927X. The observed mean lengths of whole larvae of all seven instars were near those predicted by the regression line logeY = −.5234 +.3238X but with relatively large standard deviations. Thus there were geometric increases in size between successive instars.


1991 ◽  
Vol 69 (8) ◽  
pp. 2168-2177 ◽  
Author(s):  
D. Christopher Darling ◽  
Terry D. Miller

Species of Chrysolampus are widely distributed in arid regions of western North America and parasitize tychiine weevils that infest the seed pods of legumes. Detailed host information is presented for the first time: Chrysolampus sisymbrii parasitizes Tychius tectus in Astragalus inflexus and Chrysolampus schwarzi parasitizes Tychius lineellus in Lupinus leucophyllus. Data are presented on phenology, sex ratio, mating and oviposition behaviour of adults, and behaviour and development of larvae and pupae. Ovipositional promiscuity (i.e., eggs are equally likely to be laid in pods infested or uninfested with weevil larvae) is documented in both species of Chrysolampus and discussed from a historical perspective. The immature stages of C. sisymbrii and C. schwarzi are described and illustrated using both light and scanning electron microscopy, and hypermetamorphic development is documented; the first-instar larva is morphologically distinct from the remaining larval instars. On the basis of both life history and morphology it is appropriate to refer to the first-instar larvae as planidia. The first-instar larva is sclerotized, mobile, and actively involved in host location and attack, and it is regarded as homologous to the planidia of the Eucharitidae and Perilampidae. Previous phylogenetic hypotheses regarding Chrysolampus, the Eucharitidae, and the Perilampidae are reevaluated and discussed in light of these new morphological, behavioural, and ecological data.


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