The snail Bulinus nasutus 1214 possesses a potent haemagglutinin (end-point titre with human erythrocytes, 2−18) in its cell-free haemolymph which also binds to the miracidia (but not other larvae) of the incompatible parasite Schistosoma margrebowiei. We have purified a protein possessing this haemagglutinating property from the plasma of this snail. The native Mr of this protein was estimated by SDS polyacrylamide gel electrophoresis to be 210 kDa; under denaturing conditions in a 7.5% PAGE gel it ran as a major band of 135 kDa. Proteins of similar Mr were also found in the haemolymph of 16 other Bulinus spp. (the major intermediate hosts of human and veterinary schistosomiasis in Africa) although the plasma of none of these agglutinated human erythrocytes. Nonetheless, Cleveland mapping of the Mr 135 kDa bands from these different Bulinus spp. revealed 4 identical major peptide fragments (30, 28, 19 and 16 kDa) in each, thus demonstrating a similarity in the primary structure of these plasma proteins. Antisera from Balb/C mice immunized with the 135 kDa polypeptide from Bulinus truncatus 1521 cross-reacted in Western blots with the 135 kDa band of other members of the same truncatus/tropicus species complex but not with species from the africanus or forskalii species groups.

The effects of diet on quantitative nutritional indices were measured in fifth-instar female nymphs of the grasshopper, Euprepocnemis plorans. Analysis of the main and interactive effects of feeding on the host plants lupine (Lupinus termis), horsebean (Vicia faba) or clover (Trifolium alexandrinum) and some of the plants' allelochemicals indicated that nymph performance was adversely affected by the hydrogen cyanide (HCN) and quinolizidine in horsebean and lupine respectively. Assimilation of clover was higher than of lupine or horsebean. Relative growth rate (RGR) was significantly higher in grasshoppers fed on clover than in those fed on either lupine or horsebean. Relative consumption rate (RCR) was in the order lupine > clover > horsebean. The efficiency of the digested and ingested food conversion were significantly lower in grasshoppers fed on lupine or horsebean than those fed on clover. The duration of the fifth instar was in the order horsebean > lupine > clover. Grasshoppers fed on horsebean or lupine lost weight during the experiment, with a greater weight loss recorded in those fed on horsebean. Grasshoppers contained the highest concentration of haemolymph proteins when fed on clover. Short-term feeding on lupine and horsebean resulted in 10 and 20 % mortality respectively, and nymphs that died on a horsebean diet were malformed.

The haemolymph of the tsetse, Glossina morsitans morsitans, contains a low molecular weight protein of very high density (1.29 g/mi). The protein was detected in the haemolymph during all developmental stages of the insect. Purification of the protein was achieved by a combination of density gradient ultracentrifugation and repeated gel permeation chromatography. Electrophoresis under non-denaturing and denaturing conditions showed the protein to be a single polypeptide chain (M,˜23,000). Amino acid analysis revealed a relatively high content of the acidic amino acids as well as serine and glycine. The protein contained lipids as shown by Sudan Black staining but was nonglycosylated. Using rabbit antiserum against the isolated protein in immunodiffusion and immunoblotting experiments, no cross-reactivity was detected with haemolymph samples from insects representing six orders. Although the function of the protein remains unknown, its uniqueness to Glossina suggests that it may have a role in the physiology of this insect.