Lonchaea hackmani (Lonchaeidae), Kovalev, 1981

Rotheray, Graham & Lyszkowski, Richard, 2015, Diverse mechanisms of feeding and movement in Cyclorrhaphan larvae (Diptera), Journal of Natural History 49 (35), pp. 2139-2211 : 2166

Lonchaea hackmani (Lonchaeidae)

and Neophyllomyza acyglossa (Milichiidae)

These larvae feed particularly on biofilm in cracks and crevices and coating networks of fibres ( Figure 28 , Table 1). During locomotion they are able to move forwards by gripping the substrate with the abdomen alone, and great flexibility and range of movement exists in the front body compartment and the head skeleton. For instance, the prothorax and head skeleton can twist and pivot from side to side (Film 13) and the prothorax can fold on itself ( Figures 29 and 30 ). In L. hackmani , the prothorax can rotate 360 degrees (Film 13) and, uniquely, the intermediate sclerite of N. acyglossa can bend (Film 14, Figure 31A–D ). Lunge distances were, however, the shortest recorded ( Table 2). Yet lunge times differed, being the second fastest in L. hackmani and the slowest in N. acyglossa ( Table 2). Also, relative to other saprophages, mandibles and oral cavities were relatively small, but the relative thorax length was neither long nor short although the thorax taper was the highest recorded ( Table 3). Cibarial ridges are lacking and, in both species, the basal sclerite is distinctive being not greatly sclerotised with a short ventral cornu ( Figure 32 ). The intermediate sclerite of N. acyglossa is uniquely long ( Figure 32 ).

Figures

Figure 28. Lonchaea hackmani, development site, convoluted substrate with wet decay under bark of fallen Populus tremula, Scotland, Inverness-shire, Strathspey, April 2013.

Figure 29. Lonchaea hackmani, prothorax unfolding during a lunge, still from Film 13.

Figure 30. Neophyllomyza acyglossa, prothorax unfolding during a lunge, still from a film.

Figures 31. Neophyllomyza acyglossa. (A) Preserved larva, anterior end, lateral view, length 4.5 mm. Lunging, stills from Film 14: (B) limit of forward extension; (C) bending of the intermediate sclerite; (D) limit of bending in the intermediate sclerite.

Figure 32. Neophyllomyza acyglossa, head skeleton, in situ lateral view from a puparium, length 0.4 mm.