Finding eggs and caterpillars is not always easy for many species of butterflies. However, there are a handful of helpful tips and techniques that make finding immatures easier as applicable to different species or species groups.
The key to finding butterfly eggs in the field is dependent upon an understanding of female oviposition preferences. When it comes to finding butterfly caterpillars in the field, first, it's important to familiarize yourself with where eggs are likely to have been laid. More.
Once you understand how and where to look for eggs, the next step to understanding how to find butterfly caterpillars has to do not only with the location, height, and isolation of its larval host plants, caterpillar resting preferences, but also, and most importantly, with caterpillar feeding damage (and associated nests) as evidenced on its larval host plants.
These visual queues will be reviewed in the following picture galleries:
While looking for caterpillars in the field, you will first notice that many bugs will chew on leaves. Butterfly caterpillar feeding damage as compared to moth caterpillar feeding damage or those from other insects can be unique and traceable to certain butterfly species or species groups.
This photo gallery shows some examples of differing types of butterfly caterpillar feeding damage and can help improve your chances of finding butterfly caterpillars in the field.
Skipper Nests (53)Larvae of most grass-feeding (hesperine) and spread-wing (pyrgine) skippers make nests by strategically silking together the edges of grass blades or by cutting away portions of a leaf and attaching to the same or another leaf with silken thread strands. With a little practice in the field, coupled with photographs provided within this gallery, these silken thread strands that support these nests can become easily recognizable as compared to moth caterpillar silken nests.
Another difference between skipper larval nests and moth larval nests is that skippers will exit their rolled-up leaf nest in order to launch frass whereas most moth caterpillars do not. In other words, if you find a rolled-up leaf nest with frass inside the nest, it was created by a moth caterpillar; not a skipper caterpillar.
Nymphalid Nests (5)Brushfoot butterflies such painted ladies (Vanessa cardui), red admirals (Vanessa atalanta rubria), west coast ladies (Vanessa carye annabella), American ladies (Vanessa virginiensis), milberts tortoiseshells (Nymphalis milberti), California tortoiseshells (Nymphalis californica), mourning cloaks (Nymphalis antiopa), and satyr commas (Polygonia satyrus) create nests or leaf shelters on their host plants.
Click here to watch a video on how to distinguish Polygonia satyrus neomarsyas larval nests vs. those made by Nymphalis milberti furcillata and Vanessa atalanta rubria.
Early instar caterpillars of some species groups of butterflies are gregarious; which means large groups of caterpillars feed in unison on their host plant. In North America, these groups include pine whites and brushfooted butterflies of the genera Asterocampa, Nymphalis, Chlosyne, Euphydryas, Thessalia, Poladryas, and Phyciodes.
Giant Skippers of the genera Megathymus and Agathymus create unique tents on or near their host Yucca plants or trap doors on their host Agave plants.
Swallowtail Pads (5)Late instar swallowtails belonging to the glaucus group, prefer to create an obvious silk pad on the leaf where they rest.
Admiral Perches (9)First, second, and third instar caterpillars of admirals, viceroys, and sisters belonging to the genera Limenitis and Adelpha--construct a conspicuous perch by feeding around the vein of the leaf and then extending that vein with dung pellets.
They also create a small "ball of debris" that dangles adjacent to this perch. Practice in the field searching for these perches makes it not too difficult to find caterpillars.
Admiral Hibernacula (11)Third instar caterpillars of the subgenus Basilarchia that feed on willows, cottonwoods, aspens, service berries, cherries, and other trees construct a rolled leaf hibernaculum and then overwinter inside it.
Recognizing and finding hibernacula is not too difficult; especially during the winter months when the leaves have fallen from the trees and the hibernacula remain.
Looking for camouflaged lycaenid (hairstreak or blue) caterpillars on its host plant leaves or flowers can sometimes be difficult and time consuming.
One technique that can help is to understand which species of blues or hairstreaks are tended by ants; and then look for congregations of ants on the host plant that might be tending caterpillars.
Ants tend some lycaenid caterpillars because the larvae secrete a sweet substance that the ants can consume without harming the larvae. (Ants also tend aphids; which can be annoying when looking for lycaenid larvae.) Click on any image below to start slide show.
Click here to watch video.
With Batesian and Mullerian mimicry, adult butterflies will often mimic other butterflies that are distasteful to birds. At the same time, some butterfly caterpillars will mimic bird lime in order to dissuade birds from eating them.
There are many species of butterflies where their caterpillars will camouflage themselves beautifully against the coloration, structure, and background of their host plant in order to protect themselves.
As indra immatures grow, they change their feeding damage evidence and preferred resting places change.
Some blues and metalmark caterpillars will drill a hole and burrow into the hostplant. The key to finding these caterpillars is simply by looking for a hole in the stem or flowers of the host plant.