The Bug Blog

The purpose of the Bug Blog is to provide information about and a forum for discussing the insects and other arthropods commonly encountered in Marin and Sonoma counties. Insect identification is a free service offered by the Marin/Sonoma Mosquito & Vector Control District. If you have an insect or arthropod that you would like identified, you may mail it to District headquarters (attn: Eric Engh) or drop it off (in an enclosed container) at our front desk during regular office hours. Specimens will be identified as time permits.  

Tobacco hornworm

Where found: 
In a Rohnert Park tomato garden
Size: 
Approx. 80 mm long (mature caterpillar/larva)
Scientific name: 
Manduca sexta

In the fall, a resident brought us a massive hornworm he had found on a tomato plant in his garden (see photo). Hornworms are the larval (caterpillar) stage of a moth with a wingspan of up to five inches.

Our hungry green giant, the tobacco hornworm

Hornworm pupa

The hornworm was not as healthy as we thought!

Oak moth

Where found: 
On and around coast live oaks
Size: 
Approx.13mm long (body length)
Scientific name: 
Phryganidia californica

Oak moths are the adult stage of the California oakworm.

An adult California oak moth

Two pupal cases- the yellow one is newly formed

California oakworm (larvae)

Where found: 
On and around coast live oaks
Size: 
Approx. 20mm long
Scientific name: 
Phryganidia californica

California oakworms are the larval (caterpillar) stage of the oak moth. These caterpillars feed on oak leaves, especially those of the coast live oak (Quercus agrifolia).

California oakworm caterpillars (larvae)

Oakworm frass (droppings)

Varied Carpet Beetle

Where found: 
Indoors
Size: 
Approx. 4-5mm (body length of mature larvae)
Scientific name: 
Anthrenus verbasci

Carpet beetles are an important part of nature's "clean up crew", but can damage certain items such as natural fabrics, carpets, and even preserved animal specimens (like that wild boar head mounted above your fireplace).

Classification: 

Carpet beetle larvae have specialized defensive hairs

A Seed Bug

Where found: 
In the house, falling from a skylight
Size: 
3-4mm (body length)
Scientific name: 
Metapoplax ditimoides

The seed bug Metapoplax ditimoides (family: Oxycarenidae) is relatively new to our area. Originally from the Mediterranean, it was first detected on the west coast in Oregon in 1998, and in Sonoma County in 2002. 

Classification: 

Metapoplax ditimoides, an unwelcome indoor guest

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