Question

In cockroach, thermoreceptor sensillae are located on

• A. Antennae on head
• B. Labrum of mouth parts
• C. Tarsi of legs
• D. Maxillary palps of maxilla

Hint:

In insects, sensory organs are specialized for their functions: \textbf{Antennae:} Primarily olfaction and touch. \textbf{Mouthparts (labrum, palps):} Taste and touch related to food. \textbf{Legs (tarsi):} Mechanoreception, chemoreception, and thermoreception for surface interactions.

Answer 1

The Correct Option is C

Step 1: Understand Thermoreceptor Sensillae in Cockroaches
Thermoreceptor sensillae are sensory structures in insects that detect changes in temperature. Cockroaches, like many insects, have various types of sensillae on different body parts that serve different sensory functions. Step 2: Evaluate the location of thermoreceptors in cockroaches based on common biological knowledge.
% Option (1) Antennae on head: Antennae are primary sensory organs in insects, often housing olfactory (smell), tactile (touch), and sometimes humidity receptors. While they are highly sensitive, they are not typically identified as the primary location for thermoreceptors in cockroaches.
% Option (2) Labrum of mouth parts: The labrum is part of the mouthparts, involved in feeding. While some chemoreceptors might be present, it's not a known primary location for thermoreceptors.
% Option (3) Tarsi of legs: The tarsi are the outermost segments of the legs in insects, often equipped with various sensillae. In cockroaches and other insects, thermoreceptors, as well as chemoreceptors and mechanoreceptors, are known to be present on the tarsi, allowing them to sense temperature differences on surfaces they walk on.
% Option (4) Maxillary palps of maxilla: Maxillary palps are also part of the mouthparts, primarily involved in taste and touch during feeding. While they have sensory functions, they are not typically highlighted as the main location for thermoreceptors. Step 3: Conclude the correct location.
Based on entomological studies, thermoreceptors in cockroaches are indeed found on the tarsi of their legs, allowing them to detect temperature variations in their environment, particularly on surfaces.