Immature Stages of Phycitidae
Detailed information on immature stages of Phycitidae is being acquired However, Clausen (1940) discussed the family in some length. This largely phytophagous of scavenger family contains several species which feed entirely on other insects, especially in the orders Lepidoptera and Homoptera. Phytica dentilinella Hamp. is a predator of pupae of several Lepidoptera in India. During some seasons it is found abundantly in cocoons of the nettle grub, Parasa lepida Cram. (Ayyar 1929). It is thought that the young Phycita larva reaches the host prior to cocoon formation. Infested cocoons have thinner walls than those of healthy hosts, and this indicates a certain amount of feeding by the predator larva while the host was still active (Clausen 1940/1962).
An undescribed species from southern Africa was studied by van der Merwe (1921). One to 6 1st instar larvae were found on almost mature larvae of Dasychira extorta on the foliage of fig trees. Feeding was very extensive on the body fluids of the Dasychira larva, and after its death the predator may move to another host. Oviposition was not observed, but eggs were found on cast skins. The young larvae apparently do not feed extensively until the host spins its cocoon. Thereafter occurs a rather long resting period, after which either the host larva or the pupa is quickly consumed. Mature larvae measure 25 mm. long, and the larval period ranges from 6-12 months, and the pupal period from 18-30 days. Adults show mostly during late summer. Clausen (1940) believed that this species was far advanced toward obligate parasitism, because of the ability of some individuals to attain maturity on a single host.
Ayyar (1929) recorded Euzophera cocciphaga Hamp. as a predator on the eggs and young larvae of the giant monophlebine coccid, Aspidoproctus xyliae Gr., infesting rain trees in India. The greenish-yellow eggs are laid singly on the host's dorsum, most often in the posterior region. Newly hatched caterpillars crawl about over the scale for a while but eventually find their way beneath the body. One to 3 larvae may be found beneath each scale. Shortly after feeding begins, they securely fasten the margins of the scale insect to the substratum with silken strands. This is thought to serve the purpose of preventing emergence of the host larvae after hatching. It was observed that no larvae ever emerged from parent scales known to be infested, and yet when a passageway was made through the silken barrier they emerged in numbers. Mature parasitoid larvae are grayish-green and ca. 6.5 mm. long. Pupation occurs within a tubular cocoon beneath the host remains. Other Indian species of this genus are known as stem borers or fruit feeders.
Laetilia coccidivora Comst. is a predator on the terrapin scale, Lecanium nigrofasciatum Perg., and attacks others also, particularly Ceroplastes, Icerya and Pulvinaria (Simanton 1916a). First brood eggs are laid singly among the mature scales during early June, and feeding is mainly on gravid females. A delicate silken tube is constructed from scale to scale, within which pupation occurs. Larvae of the second brood feed on the young scales during late summer. Vitula saissetiae Dyar is predaceous on Saissetia sp. in Panama, and the larvae of V. edmandii Comst. has been collected in bumblebee nests in North America (Clausen 1940/1962).
Cereobata coccophthora Turn. is predaceous on Eriococcus, and its behavior, including the provision of a dorsal shield, is quite similar to that of the noctuid Eublemma. Cryptoblabes gnidiella Mill., normally feeds on plant foliage, but it also has been observed to feed extensively on the various stages of Aleurocanthus spp. in Malaya (Clausen 1940/1962).