Injured Larvae Research Articles

Identification of hemagglutinating protein and bactericidal activity in the hemolymph of adult [formula omitted][formula omitted] on injury of the body wall

When the body wall of adult Sarcophaga peregrina (flesh-fly) was injured with a hypodermic needle, hemagglutinating activity and antibacterial activity were induced in the hemolymph simultaneously. The hemagglutinating activity was shown to be due to the same lectin that was found previously in the hemolymph of injured larvae. Thus, larval and adult Sarcophaga respond in the same way to injury of the body wall.

Purification of lectin induced in the hemolymph of Sarcophaga peregrina larvae on injury.

A lectin was purified from the hemolymph of Sarcophaga peregrina larvae, obtained after injury of their body wall. This lectin agglutinated sheep red blood cells markedly and the hemagglutinating activity was inhibited by galactose and lactose. The active lectin was found to have a molecular weight of 190,000 and to consist of four alpha subunits and two beta subunits, with molecular weights of 32,000 and 30,000, respectively. During the early pupal stage, similar hemagglutinating activity in the hemolymph increased to several times than in larval hemolymph. This activity was completely inhibited by the antibody prepared against the lectin purified from the hemolymph of injured larvae. Thus, the same protein having lectin activity is apparently induced under two different physiological conditions: injury of the body wall of larvae and during pupation. The biological significance of this lectin is discussed.

The pathogenicity of Fusarium oxysporum to mosquito larvae

Fusarium oxysporum was isolated from diseased larvae of the mosquito Aedes detritus collected in the marshy areas of Camargue, Southern France. The larvae of A. detritus and Culex pipeins pipiens were infected experimentally by contaminating water with conidia obtained from fungal cultures as well as by diseased cadavers. More than 80% mortality was obtained in the laboratory. Injured and young larvae demonstrated increased susceptibility to fungal infection. Histological preparations showed that spores germinating in the intestinal lumen were able to cause infection and the mycelium thus produced infected all tissues. Current experiments have shown that the fungus remains active even in greater quantities of water. Thus the disease may be considered as a possible limiting factor for mosquito populations, and eventually its use in biological control of mosquitoes merits further investigation.

Oxygen sensitivity in the insect Prodenia eridania.

Both the larval and pupal stages of prodenia eridania are injured by oxygen at increased pressures. The injury is manifested by a reduction in the rate of oxygen consumption, muscular paralysis and failure to develop to the adult stage. In the pupae these effects appear together as a syndrome. Pupae are much more sensitive than larvae. At least 75 psi of oxygen is necessary for injury to larvae while only 45 psi is required to produce injury in the pupae. Injured pupae respire at a rate 2%–5% of the controls while the injured larvae consume oxygen at 60% of the control rate. In attempts to modify this sensitivity by pretreatment with agents which reduce the metabolic rate, it was found that pupae kept at –10°C for 30 minutes before treatment or kept in carbon monoxide or nitrogen for 30 minutes prior to treatment showed none of the injurious effects of oxygen.

Tyrosinase in the blood of silk-worm, Bombyx mori L. (III) On the injured larvae.

Tyrosinase in the blood of silk-worm, Bombyx mori L. (III) On the injured larvae.

Laspeyresia Molesta as an Apple Pest

The extent of injury to apples, types of feeding, egg laying habits and late egg parasitism. Laspeyresia Molesta has been reported1 as a pest of apples but in the experience of the authors has never attained the commercial damage heretofore in Maryland that it has occasioned this past season. Examination of the orchard at College Park about the first of October showed a peculiar type of injury at the stem end in a large per cent of the cull fruit examined. Frequently this injury was a small split or abraded place near the base of the stem. Sometimes the injury was almost completely hidden by the stem being in contact along one side. In all cases, however, careful examination showed minute particles of frass near the base of the stem. Further examination disclosed that many fruits had minute particles of frass almost hidden by the calyx lobes. On cutting these injured fruits larvae in all stages, but principally in the early instars, were found. The tunnels were of two types. Usually the larvae burrowed through the fruit towards the seed cavity, sometimes directly; at other times winding channels were cut and often the entire seed capsule was destroyed, together with some of the seeds, as well. The second type followed the characteristic tunelling of the lesser apple worm just beneath the skin. These areas ran from the size of a dime to mines extending form the stem to near the calyx and involved nearly a quarter of the surface. When more than one larva was present, the apple broke down completely through a combination of soft rots and the feeding by the larvae. In leaving the fruit the worm usually cuts a sharply defined circular exit hole, often near the stem or calyx end and constructs its hibernaculum in the basin between adjacent fruits or between the slats of the basket or in the pad. This injury at College led to examination of cull apples from every part of the state except the extreme western counties. The apples showing evidence of worms were cut, the larvae collected and determined. The following table shows the relative proportion of codling moth and oriental fruit moth larvae in cull fruits.